Polyamides stabilized with organo-tin compounds



United States Patent Ofiice 3,189,575 POLYAMIDES STABILIZED WITH ORGANO-TIN COMPOUNDS Christian F. Horn, Charleston, and I-Iarry Vineyard,

South Charleston, W. Va., assignors to Union Carbide Corporation, a corporation'of New York No Drawing, Filed May 4,1959, Ser. No.- 810,525 v,

22 Claims. (Cl. 260-4535) This invention relates to the stabilization of polyamides against the degradative effects of light, heat, and air.

Linear, high molecular weight polyamides are well during the polymerization to control the molecular weight of the polyamide produced. These well known viscosity stabilizers, however, do not protect the polyamides against thedegradative effects of light, moisture, heatand/or oxygen. Such polyamides can be produced as described in US. Patent No. 2,071,253, issued to W. H. Carothers on February 16, 1937, and by the processes described in the chapterde'voted t-o polyamides in Fibers From Synthetic Polymers, Rowland Hill, Elsevier Publishing Company, New York, 1953. This text also presents a clear explanation of the methods used to arrive at the nomenclature of the various polyamides.

The synthetic, high molecular weight, linear polyamides heretofore obtained have been found to be unstable when exposed to light, heat, moisture or atmospheric oxygen. The resulting degradation impairs the physical properties to such an extent that quite often the degraded polymer fails for its intended purpose. This problem is particularly acute in textiles. where a loss in strength caused by degradation will render the fabrics or yarns less useful, and in severe cases completely useless.

It has now been found that linear, high molecular weight polyamides can be protected against the degradative 'efiects of light, heat, moisture, and/ or oxygen by adding thereto a stabilizing amount of an organic tin compound which is characterized by the presence therein of at least one direct carbon to tin bond. The polyamides stabilized in this invention are the synthetic linear fiber-forming'polyamides in which the CONH-- group is a recurring unit in the. polymer chain. Among the polyamides which can be stabilized with the stabilizers of this invention there may be mentioned, specifically, Nylon-6, Nylon-7, Nylon- 1 l, Nylon-6/ 6, Nylon-6/l0, Nylon-12, and the like, as well as mixtures thereof, and other copolyamides. For purposes of illustrating this invention, however, the examples are directed to Nylon- 6 and Nylon-7. I

Among the many types of organic tin compounds characterized by the presence therein of a direct carbon to tin bond, of which specific representative compounds have been tested and found useful in the methods of this invention, as degradation inhibitors or stabilizers, are:

(A) Tin compounds having four carbon to tin bonds,

as represented by the general formula:

wherein R represents a hydrocarbon radical or a substituted hydrocarbon radical such as alkyl, cycloalkyl, aralkyl, aryl, alkaryl and alkenyl radicals. Illustrative of suchcompounds there may be mentioned tetramethyl- 2 tin, tetraethyltin, tetrapropyltin, tetrabutyltin, tetraoctyltin, tetralauryltin, tetrakis(chloromethyl)tin, tetramethylsulfonylmethyltin, tetracyclohexyltin, tetrabenzyltin, tetrakis(2-phenylethyl)tin, tetraphenyltin,. tetra-para-tolyltin, tetra-para-methoxyphenyltin, tetra-para-nitrophen'yltin, tetravinyltin, tetraallyltin, as well as unsymmetrical compounds as exemplified by Lcyanoethyltributyltin, di-

butyldiphenyltin and various addition products-of alkyl t aralkyl-, aryland alkaryltin hydrides with unsaturated organic compounds such'as aer'ylonitrile allyl cyanide, crotononitrile, acrylamide, methyl acrylate, allyl alcohol, acrolein diethyl acetal, vinyl acetate, styrene, etc.

(B) Tin compounds havingn carbon to tin bonds and 4n intensifying bonds from tin to halogen atoms or to hydrogen atoms or to hydroxyl groups, as represented by the general formula:

. o l-n wherein R represents a hydrocarbon radical or a substituted hydrocarbon radical; X represents a halogen atom, a hydrogen atom or a hydroxyl radical; and n is an integer from 1 to 3. Illustrative of such compounds there may be mentioned trimethyltin chloride, tributyltin chloride, trioctyltin chloride, triphenyltin chloride, trimethyltin 'bro mide, tributyltin fluoride, triallyltin chloride, tributyltin hydride, triphenyltin hydride, trimethyltin hydnoxide, tributyltin hydroxide, dimethyltin dichloride, dibutyltin dichloride, dioctyltin dichloride, bis(2-phenylethyl)tin dichloride, diphenyltindichloride, ditolyltin dichloride, divinyltin dichloride, diallyltin dibromide, diallyltin diiodide, dibutyltin difluo'ride, bis(carboethoxymethyl)tin diiodide, 'bis(carbomethoxyethyl)tin dichloride, dibutyltin dihydride, butyltin trichloride, octyltintrichloride, and the like. r

(C) Tin compounds having two carbon to tin bond and an intensifying double bond from tin to oxygen or sulfur, as represented by the general formula:

. R SnY wherein R represents a hydrocarbon radical or a substituted hydrocarbon radical; and Y represents an oxygen or sulfur atom. Illustrative of such compounds there may be mentioned dimethyltin oxide, diethyltin oxide, dibutyltin oxide, dioctyltin oxide, dilauryltin oxide, diphenyl- 'tin oxide and diallyltin oxide, all prepared by hydrolysis of the corresponding dihalides, aswell as bis(2-phenylethyl)tin oxide, [CH OCH (Cl-I OCI-l CH SnO,

X 1CH2O( 5] 5110 and dibutyltin sulfide, the xs being whole integers.

(D) Tin compounds having n carbon to tin bonds and.

4n intensifying bonds from tin to oxygen, sulfur, nitrogen or phosphorus linking organic radicals, n being an integer from 1 to 3, such as tributyltin methoxide, tributyltin butoxide, tributyltin acetate, tributyltin N-piperazinylthiocarbonylmercaptide, tributyltin phosphorous dibutoxide(dibutyltributyltin phosphonite) [prepared as indicated immediately below:

NH 4 9)aSnNB (CiHaOhPCl ((hHshSnP (O C4119); NaCl] dibutyltin dimethoxide, dibutyltin dibutoxide,

3,189,575 Patented June 15, 1965 dibutyltin 'bistthiododerioxide) 1', dibutyltin bis(octyl thio- 1 glycolate), dibutyltin bis(N-morpholinylcarbonylmethylmercaptide), dibutyltin dibenzenesulfonamide, dimethyltin diacetate,,diethyltin diacetate, .dibutyltin diacetate, dioct'yltin diacetate, dilauryltin diacetate, dibutyltin dilaurate, dibutyltin maleate, dibutyltin bis(N-piperazinylthio-- carbonylmercaptide), dioctyltin bis(N-piperazinylthiocar.-

bonylmercaptide), octyltin tris(thiobutoxide ),.butyltin-tri-- acetate, and the like. (E) Polystannic compounds having carbon. to tin bonds and. intensifying bonds from tin to halogen, hy-' dragon, oxygen, sulfur, nitrogen or phosphorus, such .as

HOOSMCHQ SnOOI-T and. 1 H

HOOSnCH (Cl-IOCH CH SnOOI-I- v HOOSnC H SnOOl-I, noosncm snoorr the. x's being positive integers, bis(tributyltin)oxide; dibutyltin basic laurate, dibutyltin basic hexoxide and other polymeric organo-tin compounds containing carbon to tin bonds and preferably also intensifying bonds,'e.g., those having repeating v groups, dimersand trimers of (R' SnY) and the likein .which. the Rs may be alkyl, aryl oraralkyl radicals-and the Y's. are chalcogens such as isopropoxystearoxy polystarmate, hydroxystearoxy polystannate, poly-(dialkyltin oxides), available under-suchtrade names as Advastab,

"Nuostabe, and Therrnolite. I

(F) Stannonic. acid compounds havingacarbou to tin bond as represented by the general formula:

. H Bf snort i The. stabilizing. effect"; of?

characterized. by, thmpresencetthereirnofiattleustone direct carbon to tin .bondli's. determinedlby'comparinggtheztensilev according-to this: invention; wt

the; organic. tih compounds strengths: of: polyam-ideeyarnswwhijcir; haves stabilized have not'beenso Stabilized; Theape'rcentistrengtlnretenition afterexposure to light, moistu.re,-, aml'iorcoxyl gen:..isaxmeasu're of the etfectivenessz stabilizers;

The tensile strength was-measured accozdihgtozm v Test Method D-l'380-55Tj either aScott lfifimaeliineeor an Instron tester-were used, both-of?" which: are standard: pieces of equipment employed. in: determiningztensile strength; i i r 1 The: reduced viscosity (1,) was determinedfiat 305C; using;a;phenol-tetrachloroethane- (3.22. by weight) solvent with an. Ostwald: Eenske: Cannon. type= viscometeri. The.

but'are notto be. considered-limitative-z thereof... Parts" are by weightzunless'otherwisespecifiedg.

wherein-R" represents hydrogen, or a metal ion, ora hy- Y drocarbon radical or a substituted hydrocarbon radical;

R7 represents a monovalent hydrocarbon radical or sub-- stituted hydrocarbon radical, and y is an integer'having a. value ofl. Illustrative of such compounds therev may be mentioned methylstannonic acid, ethylstannonic acid, bu-

tylstannonic acid, octylstannonic acid,

' (CH3 N (CH 5110011 I X 1CH2SHOOH which the xs-are positiveinteg'er's, and the like; the metal saltsthereof such as the sodium, potassium, magnesium, calcium, zinc,.copper, aluminum, boron, titaniunnvanadium chromium, cobalt, nickel, bismuth, manganese, and

the like salts; as well as the esters ofsaid stannonic acids suchas the methyl, ethyl, propyl, 2-ethylhexyl, dodecyl, and the like esters thereof.

The stabilizing amount of organic 'tincompoundwhich is characterized by the presencetherein of at leastaone direct carbon to tin bond can be varied from about 0.025 to about 2. percent by weight per 100 parts of polyamide. The preferred stabilizer concentration is from about 0.1

'to about 0.25 percent by weight. Smaller or larger.

amounts canbe used if desired, but norsignificant advantage'is to be gained'thereby.

. The stabilizer can be added to the polyamide-after it is formed by any of the conventional procedures, or it can.

be includedhin the polymerization mixture prior" to the start of thereaction or during the courseof. the reactions Inclusion in the reaction; mixture before the polyamide is produced is the preferred procedure, andv results in: the most significant improvements in strength retention or stabilization. It is also within the scope ofthis invention to employtwo or more of the organic tinstabilizcrs, or one or more of the organic tin stabilizers together with known stabilizers such as chromic acetate, copper salicylate, and the like.

, @EXAMPLEJ v Nylon-7 prepolyrnen was produced; by; beating -68:2. parts of ethylfT-irminoheptanoate and: 60 1 parts-of: water.

at to 156 .C; foriabout 4 hours at: atmospheric pressure while passing a gentler stream. of nitrogen-11011 liter;

per: minute) throughthe melt-bymeans- 0E a. line gas spai'ger fixed. atthebottom of the. reacton. The molten prepolymer mixture: was.v cooled? to. room: temperature; and; the prepolymer was chipped and; dried Titer-solid;

white. Nylon-7 prepoly'merhad; a." reduced viscosity; of.

about 0.1 I

' In the: following examples, the NyloneTprepolymers' used were produced: by the;aboveedescribediprocedurea EX MPLE:

There were. charged 200 grams" of Nylon-7" prepolymer,

l.l14 grams of' 'adipic acid asviscositystabiliZenandOl' gram of" dibutyltin' oxide" asdegradation; inhibitor to a.-

glass condensation. vessel equipped with a sparger: at, thev bottomotthe-reacton- The reaction mi'xturewaszthen; heated"to.280" C., whilexa stream offnitrogen:waspgassed.v

through 1 themelt- .to provide. an' oxygenefreeatmosphere:

andto afford. agitation tofacilitate:- removal of; volatile-- materials: formed 'during the condensation: Thetreactiona mixture.- was kepti at' 280 C. for foun'liours; withithei nitrogen flow passing? through. the; melt: at the following.

rates: fi'rstahour, 0.25 to' 1 l'it-enper minuteeaseenndihour, j

1 to l liters per u'linute;v third and'fourthi hours; 25 to 3; liters per minute: Aftercooling. the: Nylon-'7 polymer was removed, chipped, and. driedgovernight in; a vacuum; oven at" 80" C. The: white Nylon=7'had.ia-reducedyvis-- cosityoir 1.18' and; airmelting pointof 223 'C..

The dried polymer"chips"were.nieltrspun'intqyams by' conventional: procedures; 1 on; an experimental. scale: melt.

spinning machine... The resin. was melt spun: at 2501C. using" a130h0le 0.015 inch: die-z spinning head, an; orifice velocity of 3 feet penrninute; andatakempspeed-of feetper minute; yielding filaments of about 100.; denier.

Control samples of Nylon-7' were..-prepared. using; the. same procedure as described: immediately;- abovet butv omitting'thc dibulyltin-oxidc degradation inhibitor These samples are designated A and It in lahlc. I;

Table. [lists examples 2 to l), which werc'prcpa'retlihythe procedure. described in Example: 2'. 'lfhe-.ter |sile strengths of thcyarns exposed to light; wel'edelcrmincd on.

21 Scott 1P machine; whereas the tensile; strengths of the yarns exposed to heat andoxygen were determined.

yamswwhich:

drying in a vacuum oven, the blend was melt spun into yarns as described .inlExample v2.

EXAMPLE 23 A blend of Nylon-'6 having a viscosity of 1.57 and conafter exposure of the yarns for 120 hours in an Atlas Fade- 6 Ometer. Heat and oxygen stability wa determined after taining 0.2% by weightof dibutyltin oxide was treated exposure of the yarnsin a 205 C. air circulating oven and spun into yarns as describediin-Example 22. for the periods of time indicated.

- Table l Example- A B 2 3 4' 5 6 v7 8 9 N lon-7, prepolymer, g 4,100 1 200 200 ,200 200 150 150 200 150 Adiplcaeid,g 16.773 1.114 1.114 1.394 1.394 1.394 0.9 0.9 1.394 1.046 Degradation inhibitor, g..

Dlbutyltin oxide .2 0.1 0.4 0.4 0. 75 Tetraphenyltin I 0. 2 Tetraoety 0. 15 Tributyltin hydroxide Tributyltin chloride Dibutyltributyltinphosphonite Dihutyltin bis (dilaurylnicrcaptide) Dlbutyltin dilaurate- Dlphenyltin dichloride Dibutylfln (lihm ll'rmamidl Butyltin trtchloride Octyl 4 min swirl Hydroxystearoxy polystannate--- Reduced viscosity 1.46 1.40 1.18 1.30 1.21 1.41 1. 25- 1.19 1.14 1.10 Light stability, tensile strength, g./den

Initial 5.00 6.11 5.30 5.60 5.30 5.30 4.30 1.01 4.91 3.20 4.90 4.60 3.40 3.45 20.2 80.4 60.3 87.6 80.8 64.2 8.02

5.09 4. 69' 4.77 4.60 4.81 5.06 After exposure:

lhour 2.66 4.08 2.77 3.86 4.05 3.85 3.49 4hours 1.68 Percent retention:

lhour 40.4 80.0 58.9 81.0 88.0 80.0 09.0 v honrs 25.7

Fxamnlp 10 11 12 13 14 15 16 17 1s 19 Nylon-7 prepolymer, g..- 150 150 150 150 150 150 115 115 150 150 Adipie ac1d,g 1.046 1.046 0.069 1.046 1.040 1.046 0.948 0.948 1.046 1.046 Degradation inhibitor, g..

Dibutyltin oxide Tetraphenyltin Tetraoctyl'rin Tributyltin hydroxide 0.15 Tributyltin chloride 0. 15 Dibutyltrlbutylrinnhrrsnhnnitp 0 15 Dlbutyltin bis-(dilaurylmercaptide 0. 15 Dibutyltin imam-ate" Dlphenyltin ide 0. 15 Dibutylin dibenzensultonamide Butyltin triehloride Oetylstannonic acid Hydroxystearoxy poly mmmt Reduced viscosity 1. 18 1. 22 1. 37 1.16 1. 32 .Light stability, tensile strength, gJdenier:

Initial 4.00 4.30 4.52 4.30 4.10 4.80 2.47 1.52 3.93 2.01 2.37 1.81 Percent retention 61. 7 35. 3 86. 8 46. 6 57. 8 37.? Heat and oxygen stability, tensile strength,

gJdenier:

Initi 3.92 4.13 3.94 3.85 4. 72 4.23 After exposure:

;v lhour 3.22 2.89 3.35 3.37 2.98 3.47

4 hnure 1. 97 2. 56 Percent retention:

lhour 82.0 70.0 85.0 87.4 63.0 82.0 80.0 79.0 72.0 94.5 4 11mm 50. 0 66. 5 67. 4

EXAMPLE EXAMPLE 24 A blend f 120 grams'of Nylonq, which had a reduced 60 A mixture of 200 grains of ethyl 7-aminoheptanoate, viscosity, of 1.11, and 0.24 gram of dibutyltin oxide was 200 gramslof water. 7 g of t y y a oprepared and melt cast into a mi The rod was then ate, and 0.08 gram of dibutyltm mode was heated in a chipped, dried in a vacuum oven, and the dried resin was glassreactlon vessel at to C. for 3 hours while melt Spunjmo yams as described in Example passing a gentle stream of n1trogen (0.1 literv per minute) I 60 through the melt by means of a fine gas sparger fixed at EXAMPLE 21 the bottom of the reactor. The temperature was graduall raised to about 200 C. over a A hour r' A blend of Nylon-7 having a reduced viscosity of 1.28 pe god to distill the water and ethanol. The prepolymer 1n the and containing 0.2% by weight of dibutyltin oxide was 9 treated and S un into arms as described in Exam 1 20 reaction flask was then heated to 280 C. and converted p y P e 70 to high molecular weight Nylon-7 by heating at 280 C. for 4 hours while passing nitrogen through the melt The EXAMPLE 22 Nylon-7'produced-was white, and had a reduced viscosity A blend of grams of Nylon-7 chips, which'had 3 0f reduced viscosity of 1.11, and 0.25 gram of dibutyltin EXAMPLE 25 oxide was prepared by mixing the two together. After In a manner similar to that described in Example 24,

' of dibutyltin oxide. 1

EXAMPLE 26 i In a manner similar to that described in Example 24,

Y Nylon-7 was produced from a reaction mixture of 200 grams ofethyl -7-aminoheptanoate, 200 grams of water, 0.977 gram of ethyl o-cyanohexanoate, and 03232 gram EXAMPLE 27 In a manner similar to that described in Example 24,

- Nylon-7 was produced from a reaction mixture of 200 grams of ethyl 7-amin'oheptanoate, 200grams of water,

0.977 gram of ethyl 6-cyanohexanoate, and 0.8081 gram of'dibutyltin oxide. I The'properties of the stabilized polyamides of Examples 20 to 27am tabulated in Table II. It can be seen that improved stabilization is always achieved regardless v of .the method used for incorporation of the degradation inhibitor, but that greater stabilization is obtained when the degradation inhibitor-or stabilizer is added to the forth, the results achieved with other l stabilizers ot this invention.

' What is claimed is:

1. A. composition I I linear. fiber-forming polyamide in whichjthe group is, a recurring uriit inthe polynier' ch i stabilizing amount, sufi-icientto stabili'z'e'jsaid,composition,--

of an organic tin. compoundselected from-the group cortsisting of tin compounds having from the group consisting of oxygen, sulfur, nitrogenland phosphorus linked.organic;radicals andgwherein is'an integer from I to 3 1 .ZJA composition of,.mat;ter comprising a .synthetio linear 'fiberformingl polyamide ,in which .th

.anda

stabilizing amount, sufiicient tofstabilize said composition,"

of an organic tin'compound selected from the group consisting of polystannic compounds having carbon to tin bondsandintensifying'bonds from tin to a' member selected from the group consisting of halogen, hydrogen, oxygen,sulfur, nitrogen, and phosphorus.

. 3. A' stabilized composition of matter comprising a Table Table II Example A B 20 21 22 23 24 25 26 27 Reduced viscosity 1.46 1.40 10 3 1.28 1:11 1.54 1,54 1.48 Light stability, tensile strength, g.ldenier: 1 Initial 5. 00 70 5. 58. 5. 70 5. 66 5. 61 6. 14 After exposure 1.01 2. 42 2.23 1.93 3. 61 2. 92 3. 67 Percent retentio 20. 2 51.2 40. 0 33.9 63.8 52. l 59. 8 Heat and oxygen stablht I 1 1 p gJdenier:

Initr -1 6. 57 5.01 5.8 5.97 6.68 6.7.7 5.53 4.68 5.59 After exposure 1 t 1 our 2.66 4.7 4.29 3.67 t ours 1. 69 3. 34 4.31 2. 13 3.33 2.62 3.3 2. 38 3.2-1v Percent retention: I 7

'1 hour 40.4 Y Y 69.6 77.5 78.3 4 hours 25. 7 66. 5 74. 1 35. 7 50. 0 38. 6 59. 7 51. 0 58.0

polymer zation [Bad-1011 1211161 than blended into the pre- 40 synthetic linear fiber-forming polyamide' in whichfthe' CONH group is 'a recurring unit in the polymer chain and a stabilizing amount, suflicient to stabilizesaid "composition, of 'an organic tin compound characterized by the presence therein of atleast-one direct carbon to tin bond selected from the group consisting of (A) tin compoundshaving four carbon to tin bonds'of the formula R Sn,wherein Ris a member selected from the group consisting of hydrocarbon and substituted hydrocarbon radi-' Example 30 s1 32 a4 35 as '37 39 10in Degradation inhibitor, g.:

Dimethyl oxide Diphenyltin oxide 0. 2

Thermolite 25-- Dibutyltributyltinphosphonite..

Dibutym awash",

Diootyltin maleate- Tribu ltin acetate Diocty tin nxirle Stannic phosp Stannlc phosphate and dibutyltin oxide...

Stannic phosphate and'hyd roxymaroxgpoly tnnnnta Dlbutylt oxide and dibutyltributyltinnhn nhnnHZP flydrox'ystearoxypolystannate and copper salicy a 'Hydroxystearoxypolystannate u and chromic acetate- I 'Hydroxystearoxypolystannste.-.

Dibghyltin bis-(dilaurylr'nercap- Hydroxystearoxy polystannate Reduced viscosity Light stability,tensile strength, g./

denier:

Initial 4.1 I Alter exposure- Pereent'retention; Heat and oxygen stability tensile strength, gJdenier:

Initial After exposure, 4 hours.-. Percent retention, 4 hours 6.83 i v 4a.:

sown

of V comprising a synthetic t di !0. w fl and 4'n intensifyingsbonds from .tin to a"rneinber;selected;

. 9 cals, (B) tincompounds having n carbon to tin bonds and 4-11 intensifying bonds from tin to a member selected from the group consisting of halogen, hydrogen, and hydroxyl of the formula R,,'SnX wherein X is a member selected from the group consisting of halogen, hydrogen, andhydroxyl, and n is an integer having a value of from 1' to 3, (C) tin compounds having two carbon to tin bonds andan intensifying double bond from tin to a member selected from the group consisting of oxygen and sulfur of the formula R SnY wherein Y is a member selected from the group consisting of oxygen and sulfur, (D) tin compounds having n carbon to tin bonds and 4n intensifying bonds from tin to .a member selected from the group consisting of oxygen, sulfur, nitrogen, and

phosphorus linked organic radicals, (E) polystannic compounds having carbon to tin'bonds and intensifying bonds from tin to a member selected from the group consisting of halogen, hydrogen, oxygen, sulfur, nitrogen, and phosphorus, and (F) stannonic acid compounds of the formula wherein R" is a member selectedtfrom the group consist- I ing of hydrogen, a metal atom, a hydrocarbon radical, and substituted hydrocarbon radical, R is a member selected from the group consisting of,monovalent hydrocarbon and substituted monovalent hydrocarbon radicals, and y-is an integer having a value of l.

4. A composition of matter comprising a synthetic linear fiber-forming polyamide in which the CONH group is a recurring unit in the polymer chain and from about 0.025 to about 2 percent byweight of an organic tin compound characterized by the presence therein of at least one direct carbon to tin bond selected from the group consisting of (A) tin compounds having four carbon totin bonds of the formula R Sn, wherein R is a member hydrocarbon and substituted hydrocarbon radicals, (B).

tin compounds havingn carbontotin'bonds and 4-n intensifying bonds from tin toa member selected from the group consisting of halogen, hydrogen, and hydroxyl of the formula R,,SnX wherein xtisla'member selected from the group ,consisting ..ofhalogen;- hydrogen, and hydroxyl, and n is an integerhavingavalue of from 1 to 3, (C) tin compounds having two carbon to tin: bonds and an intensifying double bond vfrom tin 'toarnember selected from the group consisting of oxygen'and sulfur of the v formula R ShY wherein Y is a memberselectedfrom the group consisting of oxygen and sulfur, (D) tin compounds having n carbon to tin bonds-and 4--n intensifying bonds from tin to a memberselected from the group consisting of oxygen, sulfur, nitrogen, and phosphorus linked organic radicals, (E) polystannic compounds having carbon to tin bonds and intensifying bonds from tin to a member selected from thegroup consisting of halogen, hydrogen, oxygen, sulfur', nitrogen, and phosphorus, and (F) stannonic acid compounds of the formula wherein R" is a member selected from the group consisting of hydrogen, a metal atom, a hydrocarbon radical,

and substituted hydrocarbon radical, R is a member 1 selected from the group consisting ofhydrocarbon and selected from the group consisting of hydrocarbon and substituted hydrocarbon radicals, (B) tin compounds having n carbon to tin bonds and4'n intensifying bonds from'tin to a member selected from the group consisting of halogen, hydrogen, and hydroxyl of the formula R,,Sn)( wheren X is a member selected'from the'group consisting of halogen, hydrogen, and hydroxyl, and n is an integer having a value of from 1 to 3, (C) tin compounds having two carbon to tin bonds and an intensifying double bond from tin to a member selected from the group consisting of oxygen and sulfur of the formula R SnY wherein Y is a member selected from the group consisting of oxygen and sulfur, (D) tin compounds having n carbon to tin bonds and 4-n intensifying bonds from tin to a member selected from the group consisting of oxygen, sulfur, nitrogen,and phosphorus linked organic radicals, (E) polystannic compounds having carbon to tin bonds and intensifying bonds from tin to a member 1 selectedfrom the group consisting of halogen, hydrogen,

oxygen, sulfur, nitrogen, and phosphorus, and (F) stannonic acid compounds of the formula wherein R" is a member selected from the group consisting of hydrogen, a metal atom, a hydrocarbon radical,

and substituted hydrocarbon radical, R is a member substituted" hydrocarbon radicals.

'7. A composition of matter comprising a synthetic linear fiber-forming polyamide in which the C.ONH- group is a recurring unit in :the polymer chain and a stabilizing amount, sufficient to stabilize said composition, of an organic tin compound selected from the group consisting of tin tcompounds' having n carbon to tin bonds and 4n intensifying bonds from tin to a member selected from the group consisting of halogen atoms, hydrogen atoms, and hydroxyl groups of the formula R SnX wherein R is a member selected from the group consisting of hydrocarbon and substituted hydrocarbon radicals, X is a member selected from the group consisting of, halogen, hydrogen, and hydroxyl, and n is an integer having a value of from 1 to 3.

8. A composition of matter comprising a synthetic linear fiber-forming polyamide' in which the CONH- group is a'recurring unit in the polymer chain: and a stabilizing amount, sufiicient to stabilize said composition, of an organic tin compound'selected from the group consisting of tin compounds having two carbon to tin bonds and an intensifying double bond from tin to-a member selected from the .groupconsisting of oxygen and sulfur atoms of the formula R SnY wherein Ris a member selected from the group consisting of'hydrocarbon andsubstitutedhydrocarbon radicalsand Y is a member selected from the group consisting of oxygen and sulfur.

9. A composition of matter comprising a synthetic linear fiber-forming polyamide in which the CONH group is a recurring unit in the polymer'chain and a stabilizing "amount, 1 sufficient to stabilize 'said composition of an organic tin compound selected fromthe-group consisting of stannonic acid compounds of the formula wherein R" is a member-selected from the group conv 11 sisting of hydrogema metal atom, a hydrocarbon radical, and, substituted hydrocarbon radical, R7 is a member selected from the group consisting of monovalent hydrocarbon and substituted monovalent hydrocarbon radicals,

and y is an integer having a value of l.

. 10. A composition of matter comprising a synthetic linear fiber-forming polyamidefin which the CONH stabilizing nt, sufiicie 'nt to stabilize said composi tion otdibntyltin oxide. r

a 11; A composition of matter comprising a synthetic linear fiber-forming polymadide in which the CONH- stabilizing amount, sufficient to stabilize said composition, of tributyltin hydroxide.

'14. -A composition of matter comprising a synthetic 1 linear fiber-forming polyamide'in which the -CONH- group 18 a recurring unit in the polymer chain and a stabilizing amount, sufiicient to" stabilize said composition, of tributyltin chloride.

15. A composition of matter comprising a synthetic linear fiber-forming polyamide in which the -CONH- group is airecurring unit in the polymer chain and a stabilizing amount, sufficient to stabilize said composition, of dibutyltributyltin phosphonite. M V

16. A composition of matter comprising a synthetic linear fiber-forming polyamide in which the CONH- group is a recurring 'unit in the polymer chain and astabilizing '-amount, sufiicient to stabilize said composition, of dibutyltin bis-(dilaurylmercaptide).

17. A composition of matter comprising a synthetic linear fiber-forming polyamide in which the CONH- group is a recurring unit in the polymer chainand a stabilizing amount, sufficient tostabilize said composition, of 'dibutyltin dichloride.

linear fiber-forming polyamide in which the -CONH groupis a recurring unit 'in the polymer chain and a group isa recurring unit in the polymerchain and a stabilizing amount, sufficient 'to stabilize-said composiv tion, of ilibutyltin dila'ur-ate'.

19. A composition of matter comprising a synthetic linear fiber-forming polyamidein which the -'CONH groupfis a recurri'ng unitin'the polymerwchain andxa" stabilizing amount, Isufii-cient to stabilizejsaidcomposie" tion, of dibutyltin'dibenzenesulfonamider stabilizing' amo unt, siiflicient"tostabilize' said coinposi- -20.A composition of matter comprising a synthetic linear fiber-forming polyamide in which the -CONH- group is a recurring unit in;the..polymer..chain and a stabilizing amount, sufficient to. stabilize said composition,'o' butyltin trichloride. 1

1 21. A composition-of matter comprising. 'a synthetic linear fiber-forming polyamide in whichthe '-CONH- group is a recurring unit in, the polymer chain and a tion, of octylstannonic acid, 1

22. A composition of" matter comprising a synthetic linear fiber-forming polyamide in which-the ''CONH group is a recurring'unit' in the polymer-chain and a stabilizing amount," sufficient "to lstabilize said compositron of hydroxystearoXy polystann-ate. 1

1 "References Cited by the Examiner ,UNITED" STATES PATENTS 2,615,860 10/52 Burgess.

2,640,044 5/53 Stamatotf 260-457 2,641,596 6/53 Leistner et al. 260-4575 2,665,265 l/54 Burges s. r 2,885,415 5/59 Ramsden .s 26045.75 2,891,922 6/59 Johnson 260-4575 2,924,586 2/60 Lotz etal; "-2,985,621'- S/6L Brandes et al;' a. 2604 5.75

3,014,956 12/61 Birum. K 3,058,941 "10/62 gBirum': 3,079,366 2/63 :Boyle'et' al.=

- p w FOREIGN PATENTS 525,590 -5/ 56 Canada. 539,161 4/57. Canada. 539,575 7 4/57 Canada. I 556,925 10/43 GreatBritain. 5/53 Great Britain.

18. A composition of matter comprising a synthetic :LEON BERCOVITZ Primary A. M. BOETTCHEK'A. D. SULLIVAN, MILTON STERMAN, J. R. LIBERMAN, Examiners.

UNITED STATES PATENT OFFICE CERTIFICATE OF CQRRECTION Patent No. 3,189,575 June 15, 1965 Christian F. Horn et a1.

It is hereby certified that error appears in the above numbered patent reqliring correction and that the said Letters Patent should read as correcteibelow.

Columns 5 and 6, Table I, ninth column, line 19 thereof, for "8.02" read 80.2 columns 7 and 8, Table II, fourth column, line 1 thereof, for "10.3" read 1.03 column 7,; line 44, for "metl" read melt Signed and sealed this 7th day of December 1965.

(SEAL) Altest:

ERNEST W. SWIDER EDWARD J. BRENNER Altosting Officer Commissioner of Patents 

4. A COMPOSITION OF MATTER COMPRISING A SYNTHETIC LINEAR FIBER-FORMING POLYAMIDE IN WHICH THE -CONHGROUP IS A RECURRING UNIT IN THE POLYMER CHAIN AND FROM ABOUT 0.025 TO ABOUT 2 PERCENT BY WEIGHT OF AN ORGANIC TIN COMPOUND CHARACTERIZED BY THE PRESENCE THEREIN OF AT LEAST ONE DIRECT CARBON TO TIN BOND SELECTED FROM THE GROUP CONSISTING OF (A) TIN COMPOUNDS HAVING FOUR CARBON TO TIN BONDS OF THE FORMULA R4SN, WHEREIN R IS A MEMBER SELECTED FROM THE GROUP CONSISTING OF HYDROCARBON AND SUBSTITUTED HYDROCARBON RADICALS, (B) TIN COMPOUNDS HAVING N CARBON TO TIN BONDS AND 4-N INTENSIFYING BONDS FROM TIN TO A MEMBER SELECTED FROM THE GROUP CONSISTING OF HALOGEN, HYDROGEN, AND HYDROXYL OF THE FORMULA RNSNX4-N WHEREIN X IS A MEMBER SELECTED FROM THE GROUP CONSISTING OF HALOGEN, HYDROGEN, AND HYDROXYL, AND N IS AN INTEGER HAVING A VALUE OF FROM 1 TO 3, (C) TIN COMPOUNDS HAVING TWO CARBON TO TIN BONDS AND AN INTENSIFYING DOUBLE BOND FROM TIN TO A MEMBER SELECTED FROM THE GROUP CONSISTING OF OXYGEN AND SULFUR OF THE FORMULA R2SNY WHEREIN Y IS A MEMBER SELECTED FROM THE GROUP CONSISTING OF OXYGEN AND SULFUR, (D) TIN COMPOUNDS HAVING N CARBON TO TIN BONDS AND 4-N INTENSIFYING BONDS FROM TIN TO A MEMBER SELECTED FROM THE GROUP CONSISTING OF OXYGEN, SULFUR, NITROGEN, AND PHOSPHORUS LINKED ORGANIC RADICALS, (E) POLYSTANNIC COMPOUNDS HAVING CARBON TO TIN BONDS AND INTENSIFYING BONDS FROM TIN TO A MEMBER SELECTED FROM THE GROUP CONSISTING OF HALOGEN, HYDROGEN, OXYGEN, SULFUR, NITROGEN, AND PHOSPHORUS, AND (F) STANNONIC ACID COMPOUNDS OF THE FORMULA 